Coaxial cables are widely used to carry high frequency electrical signals. Coaxial cables enjoy a relatively high bandwidth, low signal losses, are mechanically robust, and are relatively low cost. One particularly advantageous use of a coaxial cable is for connecting electronics at a cellular or wireless base station to an antenna mounted at the top of a nearby antenna tower. For example, the transmitter located in an equipment shelter may be connected to a transmit antenna supported by the antenna tower. Similarly, the receiver is also connected to its associated receiver antenna by a coaxial cable path.
A typical installation includes a relatively large diameter coaxial cable extending between the equipment shelter and the top of the antenna tower to thereby reduce signal losses. Some coaxial cables include a smooth outer conductor while other coaxial cables instead have a corrugated outer conductor. These coaxial cables also have an inner conductor and a dielectric between the outer conductor and the inner conductor. Some inner conductors are hollow, while other inner conductors are formed around an inner conductor dielectric core.
A typical connector for such a coaxial cable includes a connector housing to make an electrical connection to the outer conductor and a center contact to make electrical connection to the inner conductor of the coaxial cable. Such a connector may also include a back nut that is positioned onto the end of the outer conductor and adjacent the outer insulating jacket portion of the coaxial cable.
U.S. Pat. No. 5,795,188 to Harwath, for example, discloses a connector for a coaxial cable having a corrugated outer conductor. The connector includes a connector housing defining a radially outer ramp to contact the inside surface of a flared end portion of an outer conductor of the coaxial cable. A clamping ring is in the corrugation adjacent to the flared end portion of the outer conductor. The clamping ring presses the outer surface of the outer conductor against the radially outer ramp to provide electrical contact therebetween.
U.S. Pat. No. 7,011,546 to Vaccaro discloses a connector for a coaxial cable having a smooth outer conductor. The connector includes a connector housing, a back nut threadingly engaging a rearward end of the connector housing, a ferrule gripping and advancing an end of the coaxial cable into the connector housing as the back nut is tightened, and an insulator member positioned within a medial portion of the connector housing. The insulator member has a bore extending therethrough and includes a forward disk portion, a rearward disk portion, a ring portion connecting the forward and disk portions together, and a tubular outer conductor support portion extending rearwardly from the rearward disk portion for supporting an interior surface of the outer conductor of the coaxial cable.
U.S. Pat. No. 7,077,700 to Henningsen discloses a coaxial connector including a removable back nut, an outer body, and a center conductor supported within the outer body by a dielectric. An uncompressible clamp ring is rotatably disposed within the central bore of the back nut. A prepared end of a coaxial cable is inserted through the back nut, and the end portion of the outer conductor of the coaxial cable is flared outwardly. As the back nut is tightened onto the outer body, the flared end of the outer conductor is clamped between mating clamping surfaces formed on the clamp ring and the outer body.
Despite these exemplary advances in connector technology, a desire remains for connectors that install easily and maintain good electrical contact with the coaxial cable despite changes in outer conductor shape, such as may be caused by thermal expansion and/or aluminum creep.